In recent years, search services provided through a network such as the Internet have become popular. To receive the search service, the user uses, for example, an information terminal to enter one or more keywords and then send the keyword(s) to a website providing the search service through the network. The search service website detects a website, which provides information source containing the keyword(s) sent from the user, according to a predetermined algorithm, and this allows the user to browse the uniform resource locator (URL) and the like of the website on a screen of the information terminal.
Conversely, there are community sites, which are websites that provide services for information exchange among users who have interests and attributes in common and the like. When accessing a community site concerning their interests, users can share information with others by using services such as chat or electronic bulletin board, and obtain wanted information by further accessing other websites concerning their interests which are linked to the community site (see Patent Document 1, for example). [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-92028
Information exchange and communication of an interest between users are performed by a typical process: searching for websites on a search site, surveying the list of resultant websites, specifying a community site or a related website by oneself, and accessing it. However, there are numerous websites in the world today, and accordingly, in many cases, extracting sites which provide the wanted information exchange from many website hits as a search result requires significant efforts. Moreover, there may be no site concerning wanted matters because community sites and electronic bulletin boards are set up with regard to individual user's or companies′ own requirements.